Matter is conserved

Chemical elements (and water) are stored in different forms across the biosphere

Energy flows, but matter is recycled






















Each cycle includes aspects of Biology + Chemistry + Geology as elements move or are stored in the components of the biosphere in different forms or states

Importance of biogeochemical cycling: Nutrient limitation

Cycling = Transfer, transformation and storage

Biogeochemical cycles: Global

Each element will have a reservoir/s in part of the biosphere

Nutrient cycles: Ecosystem

  • Entry of nutrients into system (IN)
    • fixation (bacteria)
    • weathering (rocks)
    • deposition (acid rain)


  • Internal transfer (recycling)
    • food webs
    • decomposition
    • inorganic - organic


  • Loss of nutrients from system (OUT)
    • gas loss, leaching, disturbance


  • Steady State and Succession….

Carbon cycle: Ecosystems

Carbon cycle: Global “sinks” and “sources” of carbon

Humans vs carbon sinks and storage…

Nitrogen cycle: Ecosystems

Nitrogen cycle: Ecosystems

Decomposition - Ecosystem internal recycling

Decomposition rate: Biomes (climate+microbes+material)


Nutrient transfer: Soil commmunity

Nitrogen cycle: Global

Primary productivity: Generation of biomass

Global net primary production

Global net primary production by biome